available_toppings = ['mushrooms','olives','green peppers','pepperoni','pineapple','extra cheese']

requested_toppings = ['mushrooms','french fries','extra cheese']

for requested_topping in requested_toppings:
    if requested_topping in available_toppings:
        print("Adding " + requested_topping + ".")
    else:
        print("Sorry,we don't have " + requested_topping + ".")